1. Field of the Invention
The present invention relates to an apparatus for placement of caps, plugs, overcaps and other fitments into contact with their containers. The apparatus will pretighten the caps, plugs, overcaps and other fitments to ensure that they are squarely placed on the containers in preparation for their final closure.
2. Description of the Prior Art
Bottle capping machines have been in existence for over twenty years. On most capping machines, the system for placing caps on containers prior to tightening comprises a chute that delivers caps into the path of the containers that are being fed into the capping machine. The cap is held at an angle so that the leading edge of the cap engages the open end of the containers stripping the cap from the delivery chute so that the caps rest on the open end of the container. The containers advance to a tightening station that rotates threaded caps to a predetermined torque or presses other fitments downwardly into the container for a friction fit. Frequently, caps do not settle squarely on the container opening so that when the caps are tightened they remain out of alignment and fail to seal to the container properly.
To correct the problem generated by caps that are off-center, capping machines usually apply a strong downward force on the caps to force the caps into alignment with the container. Such force frequently damages the thread of threaded containers or the mouths of the containers resulting in caps having a failed seal. Such failed seals can permit leakage and/or contamination of the product.
The addition of tamper evident seals to the open end of containers prior to the capping operation causes increased interference with the capping process and an increased number of failures beyond those which the industry already sustained prior to these new requirements. In the alternative, seals may be placed within the caps prior to the application of the caps to the containers. In either case, if the tamper evident seal is off-center, the material may become enmeshed in the cap and container threads or between the fitments and the container opening.
There is a need, therefore, for an apparatus that with a light pressure ensures that a container cap is placed squarely on the open end of a container. Such an apparatus will improve the efficiency of the capping process and reduce the number of failures.